Refactor: Rename OutgoingEmail to SendingEmail

This commit renames and refactors all instances of `OutgoingEmail` to `SendingEmail` across the codebase to improve terminology consistency and align with domain language.

- Renamed classes, interfaces, and records (e.g., `OutgoingEmailPublisher` → `SendingEmailPublisher`, `OutgoingEmailEvent` → `SendingEmailEvent`).
- Updated method signatures, parameters, and return types to use `SendingEmail`.
- Adjusted dependency injection registrations to reflect the new naming.
- Updated mappings in `EmailMappingProfile` to map `SendEmailCommand` to `SendingEmailEvent`.
- Refactored `SendEmailCommand` and its handler to work with `SendingEmailEvent`.
- Updated `EmailsController` to use `SendingEmailEvent` in the `SendEmail` action.
- Refactored integration tests to test `SendingEmailPublisher` and updated test data accordingly.
- Updated log messages, error handling, and comments to reflect the new terminology.
- Revised documentation and utility methods to use `SendingEmailEvent`.

This refactor ensures consistency, improves readability, and reduces ambiguity in the codebase.

src/core/DigitalData.MessagingService.Abstraction/IOutgoingEmailPublisher.cs

@@ -3,9 +3,9 @@ namespace DigitalData.MessagingService.Abstraction;
 /// <summary>
 /// Email queue interface for outgoing emails.
 /// </summary>
-public interface IOutgoingEmailPublisher
+public interface ISendingEmailPublisher
 {
-    Task EnqueueAsync(OutgoingEmailEvent outgoingEmailEvent, CancellationToken cancellationToken = default);
+    Task EnqueueAsync(SendingEmailEvent sendingEmailEvent, CancellationToken cancellationToken = default);
 
     Task<int> GetQueueDepthAsync(CancellationToken cancellationToken = default);
 }

src/core/DigitalData.MessagingService.Abstraction/OutgoingEmailCreateDto.cs

@@ -1,6 +1,6 @@
 namespace DigitalData.MessagingService.Abstraction;
 
-public record OutgoingEmailCreateDto
+public record SendingEmailCreateDto
 {
     /// <summary>
     /// Recipient email address

src/core/DigitalData.MessagingService.Abstraction/OutgoingEmailEvent.cs

@@ -1,6 +1,6 @@
 namespace DigitalData.MessagingService.Abstraction;
 
-public record OutgoingEmailEvent
+public record SendingEmailEvent
 {
     public Guid Id { get; set; }
 

src/core/DigitalData.MessagingService.Application/Common/Mappings/EmailMappingProfile.cs

@@ -11,9 +11,9 @@ public class EmailMappingProfile : Profile
 {
     public EmailMappingProfile()
     {
-        // SendEmailCommand -> OutgoingEmailEvent
+        // SendEmailCommand -> SendingEmailEvent
         // Sender is resolved via MediatR in the handler and set separately after mapping.
-        CreateMap<SendEmailCommand, OutgoingEmailEvent>()
+        CreateMap<SendEmailCommand, SendingEmailEvent>()
             .ForMember(dest => dest.Id, opt => opt.MapFrom(_ => Guid.NewGuid()))
             .ForMember(dest => dest.QueuedAt, opt => opt.MapFrom(_ => DateTime.Now))
             .ForMember(dest => dest.Sender, opt => opt.Ignore());

src/core/DigitalData.MessagingService.Application/EmailSending/Commands/SendEmailCommand.cs

@@ -9,7 +9,7 @@ namespace DigitalData.MessagingService.Application.EmailSending.Commands;
 /// <summary>
 /// Command to send an email (enqueue to RabbitMQ)
 /// </summary>
-public record SendEmailCommand : IRequest<OutgoingEmailEvent>
+public record SendEmailCommand : IRequest<SendingEmailEvent>
 {
     public required GetSenderQuery Sender { get; init; }
 
@@ -36,23 +36,23 @@ public record SendEmailCommand : IRequest<OutgoingEmailEvent>
 
 /// <summary>
 /// Handler for SendEmailCommand
-/// Resolves the sender account via MediatR, maps to OutgoingEmailEvent and enqueues to RabbitMQ
+/// Resolves the sender account via MediatR, maps to SendingEmailEvent and enqueues to RabbitMQ
 /// </summary>
 public class SendEmailCommandHandler(
 ISender Sender,
-IOutgoingEmailPublisher Publisher,
-IMapper Mapper) : IRequestHandler<SendEmailCommand, OutgoingEmailEvent>
+ISendingEmailPublisher Publisher,
+IMapper Mapper) : IRequestHandler<SendEmailCommand, SendingEmailEvent>
 {
-    public async Task<OutgoingEmailEvent> Handle(SendEmailCommand request, CancellationToken cancellationToken)
+    public async Task<SendingEmailEvent> Handle(SendEmailCommand request, CancellationToken cancellationToken)
     {
         var senderAccount = await Sender.Send(request.Sender, cancellationToken)
             ?? throw new NotFoundException(
                 $"No email account found for the given sender criteria (Id: {request.Sender.Id}, Username: {request.Sender.Username}).");
 
-        var outgoingEmailEvent = Mapper.Map<OutgoingEmailEvent>(request) with { Sender = senderAccount };
+        var sendingEmailEvent = Mapper.Map<SendingEmailEvent>(request) with { Sender = senderAccount };
 
         // Enqueue to RabbitMQ
-        await Publisher.EnqueueAsync(outgoingEmailEvent, cancellationToken);
-        return outgoingEmailEvent;
+        await Publisher.EnqueueAsync(sendingEmailEvent, cancellationToken);
+        return sendingEmailEvent;
     }
 }